[RESEND PATCH v2 0/3] add regmap & indirect access support

[RESEND PATCH v2 0/3] add regmap & indirect access support

[Xu Yilun]

Updated the regmap & indirect access support for spi-altera.

Patch #1 is an 1:1 replacement of of readl/writel with regmap_read/write
Patch #2 introduced a new platform_device_id to support indirect access as
         a sub device.
Patch #3 is a minor fix.

Main changes from v1:
 - Split the regmap supporting patch to 2 patches.
 - Add a new platform_device_id to support indirect access.
 - Removed the v1 patch "move driver name string to header file". Now we
   use driver name string directly.
 - Add Yilun's Signed-off-by for Patch #3.
 - Add Tom's Reviewed-by.


Matthew Gerlach (1):
  spi: altera: fix size mismatch on 64 bit processors

Xu Yilun (2):
  spi: altera: use regmap-mmio instead of direct mmio register access
  spi: altera: support indirect access to the registers

 drivers/spi/Kconfig      |   1 +
 drivers/spi/spi-altera.c | 127 +++++++++++++++++++++++++++++++++++++++--------
 2 files changed, 107 insertions(+), 21 deletions(-)

-- 
2.7.4

[RESEND PATCH v2 1/3] spi: altera: use regmap-mmio instead of direct mmio register access

[Xu Yilun]

This patch adds support for regmap. It makes preparation for supporting
different ways to access the registers.

Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by : Tom Rix <trix@redhat.com>
---
 drivers/spi/Kconfig      |  1 +
 drivers/spi/spi-altera.c | 91 ++++++++++++++++++++++++++++++++++++++----------
 2 files changed, 73 insertions(+), 19 deletions(-)

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 8f1f8fc..6d79fc7 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -59,6 +59,7 @@ comment "SPI Master Controller Drivers"
 
 config SPI_ALTERA
 	tristate "Altera SPI Controller"
+	select REGMAP_MMIO
 	help
 	  This is the driver for the Altera SPI Controller.
 
diff --git a/drivers/spi/spi-altera.c b/drivers/spi/spi-altera.c
index aa9d1a2..b215bdf 100644
--- a/drivers/spi/spi-altera.c
+++ b/drivers/spi/spi-altera.c
@@ -44,7 +44,6 @@
 #define ALTERA_SPI_MAX_CS		32
 
 struct altera_spi {
-	void __iomem *base;
 	int irq;
 	int len;
 	int count;
@@ -54,8 +53,43 @@ struct altera_spi {
 	/* data buffers */
 	const unsigned char *tx;
 	unsigned char *rx;
+
+	struct regmap *regmap;
+	struct device *dev;
+};
+
+static const struct regmap_config spi_altera_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.fast_io = true,
 };
 
+static int altr_spi_writel(struct altera_spi *hw, unsigned int reg,
+			   unsigned int val)
+{
+	int ret;
+
+	ret = regmap_write(hw->regmap, reg, val);
+	if (ret)
+		dev_err(hw->dev, "fail to write reg 0x%x val 0x%x: %d\n",
+			reg, val, ret);
+
+	return ret;
+}
+
+static int altr_spi_readl(struct altera_spi *hw, unsigned int reg,
+			  unsigned int *val)
+{
+	int ret;
+
+	ret = regmap_read(hw->regmap, reg, val);
+	if (ret)
+		dev_err(hw->dev, "fail to read reg 0x%x: %d\n", reg, ret);
+
+	return ret;
+}
+
 static inline struct altera_spi *altera_spi_to_hw(struct spi_device *sdev)
 {
 	return spi_master_get_devdata(sdev->master);
@@ -67,12 +101,13 @@ static void altera_spi_set_cs(struct spi_device *spi, bool is_high)
 
 	if (is_high) {
 		hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
-		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
-		writel(0, hw->base + ALTERA_SPI_SLAVE_SEL);
+		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
+		altr_spi_writel(hw, ALTERA_SPI_SLAVE_SEL, 0);
 	} else {
-		writel(BIT(spi->chip_select), hw->base + ALTERA_SPI_SLAVE_SEL);
+		altr_spi_writel(hw, ALTERA_SPI_SLAVE_SEL,
+				BIT(spi->chip_select));
 		hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
-		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
+		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
 	}
 }
 
@@ -99,14 +134,14 @@ static void altera_spi_tx_word(struct altera_spi *hw)
 		}
 	}
 
-	writel(txd, hw->base + ALTERA_SPI_TXDATA);
+	altr_spi_writel(hw, ALTERA_SPI_TXDATA, txd);
 }
 
 static void altera_spi_rx_word(struct altera_spi *hw)
 {
 	unsigned int rxd;
 
-	rxd = readl(hw->base + ALTERA_SPI_RXDATA);
+	altr_spi_readl(hw, ALTERA_SPI_RXDATA, &rxd);
 	if (hw->rx) {
 		switch (hw->bytes_per_word) {
 		case 1:
@@ -133,6 +168,7 @@ static int altera_spi_txrx(struct spi_master *master,
 	struct spi_device *spi, struct spi_transfer *t)
 {
 	struct altera_spi *hw = spi_master_get_devdata(master);
+	u32 val;
 
 	hw->tx = t->tx_buf;
 	hw->rx = t->rx_buf;
@@ -143,7 +179,7 @@ static int altera_spi_txrx(struct spi_master *master,
 	if (hw->irq >= 0) {
 		/* enable receive interrupt */
 		hw->imr |= ALTERA_SPI_CONTROL_IRRDY_MSK;
-		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
+		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
 
 		/* send the first byte */
 		altera_spi_tx_word(hw);
@@ -151,9 +187,13 @@ static int altera_spi_txrx(struct spi_master *master,
 		while (hw->count < hw->len) {
 			altera_spi_tx_word(hw);
 
-			while (!(readl(hw->base + ALTERA_SPI_STATUS) &
-				 ALTERA_SPI_STATUS_RRDY_MSK))
+			for (;;) {
+				altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
+				if (val & ALTERA_SPI_STATUS_RRDY_MSK)
+					break;
+
 				cpu_relax();
+			}
 
 			altera_spi_rx_word(hw);
 		}
@@ -175,7 +215,7 @@ static irqreturn_t altera_spi_irq(int irq, void *dev)
 	} else {
 		/* disable receive interrupt */
 		hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
-		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
+		altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
 
 		spi_finalize_current_transfer(master);
 	}
@@ -188,7 +228,9 @@ static int altera_spi_probe(struct platform_device *pdev)
 	struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev);
 	struct altera_spi *hw;
 	struct spi_master *master;
+	void __iomem *res;
 	int err = -ENODEV;
+	u32 val;
 	u16 i;
 
 	master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
@@ -220,19 +262,30 @@ static int altera_spi_probe(struct platform_device *pdev)
 	master->set_cs = altera_spi_set_cs;
 
 	hw = spi_master_get_devdata(master);
+	hw->dev = &pdev->dev;
 
 	/* find and map our resources */
-	hw->base = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(hw->base)) {
-		err = PTR_ERR(hw->base);
+	res = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(res)) {
+		err = PTR_ERR(res);
 		goto exit;
 	}
+
+	hw->regmap = devm_regmap_init_mmio(&pdev->dev, res,
+					   &spi_altera_config);
+	if (IS_ERR(hw->regmap)) {
+		dev_err(&pdev->dev, "regmap mmio init failed\n");
+		err = PTR_ERR(hw->regmap);
+		goto exit;
+	}
+
 	/* program defaults into the registers */
 	hw->imr = 0;		/* disable spi interrupts */
-	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
-	writel(0, hw->base + ALTERA_SPI_STATUS);	/* clear status reg */
-	if (readl(hw->base + ALTERA_SPI_STATUS) & ALTERA_SPI_STATUS_RRDY_MSK)
-		readl(hw->base + ALTERA_SPI_RXDATA);	/* flush rxdata */
+	altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
+	altr_spi_writel(hw, ALTERA_SPI_STATUS, 0);	/* clear status reg */
+	altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
+	if (val & ALTERA_SPI_STATUS_RRDY_MSK)
+		altr_spi_readl(hw, ALTERA_SPI_RXDATA, &val); /* flush rxdata */
 	/* irq is optional */
 	hw->irq = platform_get_irq(pdev, 0);
 	if (hw->irq >= 0) {
@@ -255,7 +308,7 @@ static int altera_spi_probe(struct platform_device *pdev)
 		}
 	}
 
-	dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
+	dev_info(&pdev->dev, "base %p, irq %d\n", res, hw->irq);
 
 	return 0;
 exit:
-- 
2.7.4

[RESEND PATCH v2 2/3] spi: altera: support indirect access to the registers

[Xu Yilun]

This patch adds support for indirect access to the registers via parent
regmap.

The use case is, the spi master is a sub device of a Multifunction
device, which is connected to host by some indirect bus. To support this
device type, a new platform_device_id is introduced, and the driver tries
to get parent regmap for register accessing like many MFD sub device
drivers do.

Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Reviewed-by : Tom Rix <trix@redhat.com>
---
 drivers/spi/spi-altera.c | 62 ++++++++++++++++++++++++++++++++++++------------
 1 file changed, 47 insertions(+), 15 deletions(-)

diff --git a/drivers/spi/spi-altera.c b/drivers/spi/spi-altera.c
index b215bdf..4f7717f 100644
--- a/drivers/spi/spi-altera.c
+++ b/drivers/spi/spi-altera.c
@@ -43,6 +43,11 @@
 
 #define ALTERA_SPI_MAX_CS		32
 
+enum altera_spi_type {
+	ALTERA_SPI_TYPE_UNKNOWN,
+	ALTERA_SPI_TYPE_SUBDEV,
+};
+
 struct altera_spi {
 	int irq;
 	int len;
@@ -55,6 +60,7 @@ struct altera_spi {
 	unsigned char *rx;
 
 	struct regmap *regmap;
+	u32 regoff;
 	struct device *dev;
 };
 
@@ -70,7 +76,7 @@ static int altr_spi_writel(struct altera_spi *hw, unsigned int reg,
 {
 	int ret;
 
-	ret = regmap_write(hw->regmap, reg, val);
+	ret = regmap_write(hw->regmap, hw->regoff + reg, val);
 	if (ret)
 		dev_err(hw->dev, "fail to write reg 0x%x val 0x%x: %d\n",
 			reg, val, ret);
@@ -83,7 +89,7 @@ static int altr_spi_readl(struct altera_spi *hw, unsigned int reg,
 {
 	int ret;
 
-	ret = regmap_read(hw->regmap, reg, val);
+	ret = regmap_read(hw->regmap, hw->regoff + reg, val);
 	if (ret)
 		dev_err(hw->dev, "fail to read reg 0x%x: %d\n", reg, ret);
 
@@ -225,10 +231,11 @@ static irqreturn_t altera_spi_irq(int irq, void *dev)
 
 static int altera_spi_probe(struct platform_device *pdev)
 {
+	const struct platform_device_id *platid = platform_get_device_id(pdev);
 	struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev);
+	enum altera_spi_type type = ALTERA_SPI_TYPE_UNKNOWN;
 	struct altera_spi *hw;
 	struct spi_master *master;
-	void __iomem *res;
 	int err = -ENODEV;
 	u32 val;
 	u16 i;
@@ -264,19 +271,38 @@ static int altera_spi_probe(struct platform_device *pdev)
 	hw = spi_master_get_devdata(master);
 	hw->dev = &pdev->dev;
 
+	if (platid)
+		type = platid->driver_data;
+
 	/* find and map our resources */
-	res = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(res)) {
-		err = PTR_ERR(res);
-		goto exit;
-	}
+	if (type == ALTERA_SPI_TYPE_SUBDEV) {
+		struct resource *regoff;
 
-	hw->regmap = devm_regmap_init_mmio(&pdev->dev, res,
-					   &spi_altera_config);
-	if (IS_ERR(hw->regmap)) {
-		dev_err(&pdev->dev, "regmap mmio init failed\n");
-		err = PTR_ERR(hw->regmap);
-		goto exit;
+		hw->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+		if (!hw->regmap) {
+			dev_err(&pdev->dev, "get regmap failed\n");
+			goto exit;
+		}
+
+		regoff = platform_get_resource(pdev, IORESOURCE_REG, 0);
+		if (regoff)
+			hw->regoff = regoff->start;
+	} else {
+		void __iomem *res;
+
+		res = devm_platform_ioremap_resource(pdev, 0);
+		if (IS_ERR(res)) {
+			err = PTR_ERR(res);
+			goto exit;
+		}
+
+		hw->regmap = devm_regmap_init_mmio(&pdev->dev, res,
+						   &spi_altera_config);
+		if (IS_ERR(hw->regmap)) {
+			dev_err(&pdev->dev, "regmap mmio init failed\n");
+			err = PTR_ERR(hw->regmap);
+			goto exit;
+		}
 	}
 
 	/* program defaults into the registers */
@@ -308,7 +334,7 @@ static int altera_spi_probe(struct platform_device *pdev)
 		}
 	}
 
-	dev_info(&pdev->dev, "base %p, irq %d\n", res, hw->irq);
+	dev_info(&pdev->dev, "regoff %u, irq %d\n", hw->regoff, hw->irq);
 
 	return 0;
 exit:
@@ -325,6 +351,11 @@ static const struct of_device_id altera_spi_match[] = {
 MODULE_DEVICE_TABLE(of, altera_spi_match);
 #endif /* CONFIG_OF */
 
+static const struct platform_device_id altera_spi_ids[] = {
+	{ "subdev_spi_altera", ALTERA_SPI_TYPE_SUBDEV },
+	{ }
+};
+
 static struct platform_driver altera_spi_driver = {
 	.probe = altera_spi_probe,
 	.driver = {
@@ -332,6 +363,7 @@ static struct platform_driver altera_spi_driver = {
 		.pm = NULL,
 		.of_match_table = of_match_ptr(altera_spi_match),
 	},
+	.id_table	= altera_spi_ids,
 };
 module_platform_driver(altera_spi_driver);
 
-- 
2.7.4

[RESEND PATCH v2 3/3] spi: altera: fix size mismatch on 64 bit processors

[Xu Yilun]

From: Matthew Gerlach <matthew.gerlach@linux.intel.com>

The spi-altera driver was originally written with a 32
bit processor, where sizeof(unsigned long) is 4.  On a
64 bit processor sizeof(unsigned long) is 8.  Change the structure
member to u32 to match the actual size of the control
register.

Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Xu Yilun <yilun.xu@intel.com>
Reviewed-by : Tom Rix <trix@redhat.com>
---
 drivers/spi/spi-altera.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/spi/spi-altera.c b/drivers/spi/spi-altera.c
index 4f7717f..d91c093 100644
--- a/drivers/spi/spi-altera.c
+++ b/drivers/spi/spi-altera.c
@@ -53,7 +53,7 @@ struct altera_spi {
 	int len;
 	int count;
 	int bytes_per_word;
-	unsigned long imr;
+	u32 imr;
 
 	/* data buffers */
 	const unsigned char *tx;
-- 
2.7.4

Re: [RESEND PATCH v2 0/3] add regmap & indirect access support

[Mark Brown]

On Fri, 19 Jun 2020 09:43:38 +0800, Xu Yilun wrote:
> Updated the regmap & indirect access support for spi-altera.
> 
> Patch #1 is an 1:1 replacement of of readl/writel with regmap_read/write
> Patch #2 introduced a new platform_device_id to support indirect access as
>          a sub device.
> Patch #3 is a minor fix.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/3] spi: altera: use regmap-mmio instead of direct mmio register access
      commit: 3c6519736eefebafdf8c82d46f64b214403b5260
[2/3] spi: altera: support indirect access to the registers
      commit: 3820061d38156d88443d32a9a6c701d281234746
[3/3] spi: altera: fix size mismatch on 64 bit processors
      commit: d9dd0fb0e197ae766f0f5e06d23f5f5e1888c511

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark